Cutting Back Salvia Black and Blue

Have this type of salvia in a sheltered part of the garden which is still in 2nd bloom.

They are in a bit of a frost shadow and haven't been damaged by the couple of colder evenings we recently experienced,

Do you let these salvias die off naturally before cutting back?

Is there a specific time and method?


Thanks in advance.

 

I have had Salvia guaranatica "Black and Blue" for over 10 years and it's hardy here, in bad winters it gets cut to the ground, but reemerges late spring from the the running rootstock.
I leave it until it starts to grow the next spring and then remove any dead bits and unwanted growth.

 

I agree with that. It has hollow stems and damp over the winter gets in and rots the plant from the inside out. If it is the true Black and Blue ( and not Black and Bloom) it is very hardy.

 

I had black and bloom and it died on me every winter, nice plant though.

 

Thanks for the replies.